In June 2010, Dennis and Otway began to distill more than 100 hours of footage—some 70 hours from North Carolina and 30 hours from Afghanistan—into a 90-minute documentary. They had to find a story in the footage, determine the narrative arc, assemble scenes, craft transitions, and fine-tune scene lengths. As with most documentaries, time and money were tight. They had a budget for only four months of editing. In addition, they hoped to get the film into the annual Sundance Film Festival in January 2011. The deadline for submissions was September 24, 2010.

The first challenge was establishing that the story was about Harris. In combat, it was hard to distinguish one Marine from another, and there were no cues in the opening combat scenes to indicate that the story was about any one person. After multiple rounds of test screenings and re-edits, the filmmakers were having trouble getting the story started while adhering to their approach of letting the footage speak for itself with no narrative.

Dennis and Otway reluctantly resorted to using cards containing short texts that indicated that Harris led the platoon. This gave the audience the cue it needed, says Dennis.

When Lance Corporal Sharp is killed and the story becomes about Sergeant Harris, we had to separate the two and provide clarification. And so we inserted these black cards that explained what was going on and introduced Nathan as the main character. It wasn’t enough to just simply let the images and the audio play.

Dennis and Otway continually had to choose which path to follow and which stories to tell. At one point, for example, they considered expanding on Harris’ experience with the Veterans Administration healthcare system and showing how Ashley’s burden of caring for her husband was part of the civilian toll of the war. But they discarded those sub-stories for lack of time. “Because you are so limited by time, there are just entire threads that you have to discard,” says Dennis.

One of the toughest decisions the filmmakers faced was how to integrate the footage from Afghanistan with that from North Carolina. From the beginning of the editing process, Dennis wanted to alternate between the two sets of footage rather than work chronologically. Otway wasn’t sure they’d be able to pull off the flashback structure. “In the beginning the intercutting was painful to watch and it really wasn’t working,” she says. “So that was sort of a scary period to work through until it started to fall into place.” In the end, they decided to craft a narrative from the North Carolina footage, shot largely in 2010, and intersperse scenes from the 2009 Afghanistan combat as flashbacks. “That was a very delicate process that we spent a lot of time on, the transitions between one world and the other,” says Dennis.

Flashbacks . While the flashback structure offered a creative route to integrating two sets of footage, it was ethically tricky. Dennis and Otway didn’t know what Harris was thinking or feeling in the scenes where they inserted footage from Afghanistan, yet the technique implied that the flashbacks were his experiences in those moments. As Otway recalls it, they discussed the notion of “documentary truth” and the idea of being true to the spirit of a story even if they weren’t presenting a particular instance of footage in an accurate context.

Dennis and Otway realized that they would have to craft transitions by adding sounds and altering images—cinematic techniques that manipulated the reality of the footage. The challenge was to use only as much as necessary to make the flashback structure work. Go too far and the techniques came off as gimmicks or, worse, turned the scene into fiction. The filmmakers focused on the first two transitions from North Carolina to Afghanistan to ensure that the audience understood that the transitions were flashbacks and interpreted them as Harris’ experience.

The first transition occurred when Harris was in a Wal-Mart department store looking at a combat-themed video game. Harris was staring up at a video screen off-camera. The shot was a close-up of Harris’ face. The filmmakers slowed the footage, slightly diminished the colors and faded in audio from the Afghanistan combat footage. The effect implied that Harris’ eyes had glazed over and his mental state was focused inward.

We essentially are suggesting that now you’re entering his thoughts and you’re entering his memories, and his memories have been triggered by his looking at these video games and he’s comparing it to his actual experience of war. So that’s where we’re starting to step into his mind.

Dennis describes the scene in Wal-Mart.

It was possible that in that moment Harris was actually thinking only about the video game. In the context of the film, however, the moment became a key pivot point. It established the flashback structure and cued the audience to consider the inner experience of a wounded combat veteran who had recently returned home. The scene also encapsulated Dennis’ message about how war was depicted. “We wanted that world of Wal-Mart, with all these false representations of war everywhere on sale and on the screens, to fade away,” says Dennis. “Then his memories of those real experiences replace them.”

Sounds . Sound was key to the transitions in the flashback scenes. Fading in combat sounds at the beginning of a flashback to a combat scene was a conventional film technique, and that allowed Dennis and Otway to take advantage of the viewer’s expectations. Sound was also a key element of actual flashbacks, including those Dennis experienced.

Even when you’re in the safety of the US, you’re transported in your mind back to these very difficult situations. Audio is often something that can bring you back much more quickly than anything else. A certain sound. The crack of a rifle or the hum of a helicopter. These things can instantly bring you back.

Dennis couldn’t produce the effect he was looking for from the combat footage. “He was getting frustrated because he was trying to communicate what it felt like to have to go through these experiences,” says Otway. So Dennis created subtle background sounds. “I think there was something really specific in his head that he was trying to recreate that just helped give the feeling of what it’s like to be dealing with PTSD,” she says.

Dennis worked with two sets of sounds, one metallic and warlike (helicopter blades and machine guns) and the other highly emotional human sounds (crying and cheering). He slowed these sounds to 2 or 4 percent of their original speed. “They would become these very low drones that were as close as I could come to trying to convey the emotional numbness and disorientation,” says Dennis.

Shocking images. Filmmakers who documented war often wrestled with the problem of how much violence and bloodshed to show. Dennis and Otway were no exception. Countering sanitized and glorified representations of war with brutally honest ones was a major motivation for Dennis to make his film—the working title was Battle for Hearts and Minds (eventually, they would call it Hell and Back Again ). Accurate portrayals of the consequences of war were also important for Dennis as a photojournalist.

One sequence of footage proved particularly troublesome. Dennis was on patrol with the Marines of Echo Company and several Afghan National Army soldiers when they came under fire. As they crouched behind a berm alongside a road, an improvised explosive device detonated a few feet behind Dennis. The explosion showered the Marines with dirt, and in the confusion it took them several moments to realize that one of the Afghan soldiers was missing. His body had been thrown 60 feet into the middle of a nearby field. Dennis went into the field with several Marines and Afghan soldiers and filmed them placing the mangled body on a stretcher.

In the initial drafts of the film, the filmmakers cut the scene before the graphic part. They were concerned about causing viewers to recoil. Was it effective to show a mutilated body at all? Did it turn a viewer’s emotional receptors off completely? They also thought about the possibility of the dead soldier’s family seeing the footage.

But Dennis felt it was important to convey an uncensored view of war and pushed to include the footage. Otway argued that the full scene went too far. “We definitely had several difficult conversations along the way about how much of the really graphic images we should use,” she says. They ended up using the footage. Dennis acknowledged that the most graphic part of the scene crossed a line, but he felt it was justified.

I wanted people to see what war really looks like, and not give them a sugarcoated version of it... I couldn’t portray war without the reality of it. If I had made an entire film and didn’t show the cost of war, it would be false.